1. Field of the Invention
The present invention relates generally to the field of panel structures developed for the purpose of providing relief in the event of explosions occurring within a protected enclosure, or for the relief of pressures developing to an excessive degree within said enclosures. In a more particular sense, the invention has reference to an improved panel structure having a peripheral sealing gasket especially designed to react to excessive pressures while they remain at a relatively low value, to vent the enclosure before dangerous, high pressure conditions develop therein.
2. Description of the Prior Art
It is not new, broadly, to provide relief openings in any of various types of enclosures such as, for example, processing towers, retorts, ducts, mixers, and the like. Typically, such enclosures may have relief openings that are normally sealably closed by closure panels designed to move to positions venting the enclosure when dangerous pressure conditions develop therein. Such panels, for example, provide relief in the event of an explosion within the enclosure, or alternatively, may provide relief whenever pressures rise within the enclosure to an extent determined as exceeding a safe level. In U.S. Pat. No. 4,207,706, a closure panel of this type is disclosed, utilizing a linearly movable panel member supported by pivoted arms. The disclosure of that patent is incorporated herein by reference. In that patent, a peripheral sealing gasket is disclosed, in which sealing pressures are exerted against an adjacent rim of a supporting frame in the plane of the panel itself.
The prior art arrangement, while operating satisfactorily, is not thought to react to low pressures, on the order for example of 2 to 3 inches of water, with a high degree of accuracy and repeatability. Yet, in many situations, reactions having this degree of sensitivity are clearly desirable and should be attained if at all possible.
It is important, too, to provide a unitary structure, including a support means that incorporates frame components in such a manner as to permit the entire device to be preassembled and installed as a single unit, with the frame adapted to utilize basic frame elements that will completely isolate all other frame components from the sealing function. This characteristic has been thought lacking in the prior art as exemplified by U.S. Pat. No. 4,207,706, in which the exertion of a sealing pressure in the plane of the closure panel, against a surrounding rim of the frame assembly, does not offer such isolation.
The prior art as typified by the above-designated patent is further lacking in an adaptability for reacting to low pressures while at the same time complying with industry standards relating to strength, resistance to accidental malfunction, and pressure relief values regarded as important in pressure-relieving closure panel structures.